cAd3-Marburg Vaccine in Healthy Adults

A total of 40 participants were evenly split, with 20 in each of the two dosage groups, to receive the investigational cAd3-Marburg vaccine at a dose of either 1x10^10 particle units (PU) (Group 1) or 1x10^11 PU (Group 2). The dose escalation plan included daily review of any new safety data by a study clinician, regular review of safety data by the protocol team and a staged enrollment plan with required interim safety reviews. The study began with enrollment of 3 participants into Group 1 (1x10^10 PU) at a rate of 1 participant per day. After at least 7 days of follow-up for the first 3 vaccinated participants, an interim safety review occurred before enrollment of additional participants into the group. No safety issues were identified; therefore, an additional 17 participants were enrolled to complete Group 1. When there was a minimum of seven days of follow-up safety data from the last enrolled participant in Group 1, an interim safety review occurred. Once no safety issues were identified, enrollment of participants into the next dose level began with the enrollment of 3 participants at a rate of 1 participant per day. After at least 7 days of follow-up for the first 3 vaccinated participants in Group 2 (1x10^11 PU), an interim safety review occurred before the enrollment of additional participants into Group 2. No safety issues were identified and an additional 17 participants were enrolled to complete Group 2. Participants were followed for approximately 48 weeks.

Inclusion criteria

• 18 to 50 years old
• Available for clinical follow-up through Week 48 after enrollment
• Able to provide proof of identity to the satisfaction of the study clinician completing the enrollment process. Proof of identity includes a valid U.S. government-issued or state-issued photo identification (ID) such as a driver's license, military ID, or U.S. passport.
• Able and willing to provide a personal mobile phone number or home phone number at which the participant can be reliably contacted. Participants will be contacted primarily for study visit 2A (Appendix 1), as a reminder of an upcoming visit, and after missed visits for rescheduling purposes.
• Able and willing to complete the informed consent process and demonstrate understanding with a passing score (90% or greater) on the Assessment of Understanding (AOU) by the third attempt.
• In good general health without clinically significant medical history.
• Physical examination and laboratory results without clinically significant findings and a body mass index (BMI) ≤ 40 within the 56 days prior to enrollment.
• Laboratory Criteria within 56 days prior to enrollment:

• Hemoglobin ≥ 11.5 g/dL for women; ≥13.0 g/dL for men.
• White blood cells (WBC) = 3,300-12,000 cells/mm^3.
• Total lymphocyte count ≥ 800 cells/mm^3.
• Platelets = 125,000 - 400,000/mm^3.
• Alanine aminotransferase (ALT) ≤ 1.25 x upper limit of normal.
• Serum creatinine ≤ 1 x upper limit of normal.
• HIV-uninfected as evidenced by a negative FDA-approved HIV diagnostic blood test.

Female-Specific Criteria:

• Negative β-HCG (human chorionic gonadotropin) pregnancy test; serum β-HCG at screening (or urine if screening is the same day as enrollment) and urine β-HCG at enrollment if woman is of reproductive potential.
• Agrees to use an effective means of birth control from at least 21 days prior to enrollment through 24 weeks after study vaccination if assessed to be of reproductive potential.

Exclusion criteria

Volunteer has received any of the following substances:

• Investigational Ebola or Marburg vaccine in a prior clinical trial or prior receipt of a cAd3 vectored investigational vaccine.
• Immunosuppressive medications within 2 weeks prior to enrollment.
• Blood products within 112 days (16 weeks) prior to enrollment.
• Investigational research agents within 28 days (4 weeks) prior to enrollment.
• Live attenuated vaccines within 28 days (4 weeks) prior to enrollment.
• Subunit or killed vaccines within 14 days (2 weeks) prior to enrollment.
• Current anti-tuberculosis prophylaxis or therapy.

Female-specific criteria:

• Woman who is pregnant, breast-feeding or planning to become pregnant during the first 24 weeks after study vaccine administration.

Volunteer has a history of any of the following clinically significant conditions:

• Serious adverse reactions to vaccines such as anaphylaxis, urticaria (hives), respiratory difficulty, angioedema, or abdominal pain.
• Allergic reaction to excipients in the study vaccine including gentamycin, neomycin or streptomycin.
• Clinically significant autoimmune disease or immunodeficiency.
• Asthma that is not well controlled.
• Positive syphilis serology. False-positive results will also exclude a participant.
• Diabetes mellitus (type I or II).
• Thyroid disease that is not well controlled.
• A history of hereditary angioedema (HAE), acquired angioedema (AAE), or idiopathic forms of angioedema.
• Idiopathic urticaria within the last 1 year.
• Hypertension that is not well controlled.
• Bleeding disorder diagnosed by a doctor (e.g. factor deficiency, coagulopathy, or platelet disorder requiring special precautions) or significant bruising or bleeding difficulties with intramuscular (IM) injections or blood draws.
• A malignancy that is active, currently being treated, or not surgically cured.
• Seizure in the past 3 years or treatment for seizure disorder in the past 3 years.
• Asplenia or functional asplenia.
• Psychiatric condition that precludes compliance with the protocol; past or present psychoses; or within five years prior to enrollment, history of a suicide plan or attempt.
• Any medical, psychiatric, social condition, occupational reason or other responsibility that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a volunteer's ability to give informed consent.